Jon boat mods

I have a 16ft landau jon boat. The boat works great for what I use it for but I have one problem with it. The rear seat is the normal bench type and is about 18" wide. It seems to me like the seat is to far forward of the transom. I have to use a tiller extension handle to be somewhat comfortable while steering the motor (tiller steering). I don't much care for the extension handle at all because it flexes and seems like it might come loose.

I've been thinking of removing the whole rear bench and building two new seats that would be on each side of the boat in the rear. With the center just being the floor. I know this idea would be way more comfortable for me but I was just concerned about removing the bench. The seat is actually a structural part of the boat so if I take it out I will have to build something that will keep the boat ridgid. I know i've seen boats with rear benches on both sides and nothing in the middle but how do they keep the boat from flexing?

I'd also like to build a baitwell into one of the benches using a 5 gallon bucket that will be in the seat.

I have a full fab/welding shop that I own so anything can be made, i'm just not sure how to keep the strength in the boat if I do this.
Any other options????

What about notching out the center part of the seat and adding some more foam inside the seat then sealing it back up w/ plate alumiun? Thats what father-in-law to his boat. he also had a deck put in boat diamond for no skid.. if you need pics of his boat i'll see what i could do to try and help...

You sound like a lucky guy to have a tig welder. I might be off base here but this is my idea. If I can put it in words.
Make 2 alum. boxs and tig them to the sides and bottom. Leaving the center open. This would allow the strenght you need. Plus you picked up 2 storage areas/ live wells. Bolt your seats to the tops of the lids and poof.
Bill

Remember when you are messing with jon boats you are dealing with structurally one of the weakest materials used in boat building.
Thats why jon boats have bench seats.
Take out that rear bench seat and put a motor of any size on it and you'll own an aluminum pretzel.
If you are lucky you'll just have mysterious cracks appear from bow to stern.

Thats exactly what I think the problem will be. I measured the seat and rear portion of the boat today. The seat/bench is 20" wide and from the back of the bench to the transom is 24". This makes it 44" from the front of the bench to the transom. It's a hell of a stretch trying to reach the tiller handle while also trying to face forwards to drive. I think I might move the bench forward about 12" and then build some boxes for each side going from the transom to the bench. Hopefully this will make a larger area in the rear so I could sit on one of the boxes sideways in the boat and steer. If I ad some foam to these boxes will this make the boat run in shallower water? Not real sure how that works.

Mark J said:

Remember when you are messing with jon boats you are dealing with structurally one of the weakest materials used in boat building.
Thats why jon boats have bench seats.
Take out that rear bench seat and put a motor of any size on it and you'll own an aluminum pretzel.
If you are lucky you'll just have mysterious cracks appear from bow to stern.

Nope, foam wont make it float higher.
Foam is not lighter then air. Foam actually will make a boat ride lower, although in your case that amount of foam would be unnoticeable in ride height.
Foam is used strictly to keep some portion of a boat floating and if the foam is applied right will keep a boat in the upright attitude.

First of all, a certain amount of flexing isn't necessarily going to hurt anything. My first 16' jonboat was very lightweight and only had a 36" wide bottom. Particularly when alone in the boat, I could watch the boat twist back and forth as I went over choppy water or waves from other boats. I used it a lot and never had any problems with seams opening up or rivits coming loose. The 16' Lowe BigJon I have now is a whole 'nuther boat. Not only does it have a 48" wide bottom, but it's made of thicker material, and has higher sides. I could lift the first jonboat off the ground with one hand if I grabbed it at the balance point; the BigJon weighs about 280# dry weight. There's no flex visible at any time. I wouldn't have taken a seat out of the first jonboat, but I'm planning on removing the rear seat from the BigJon and putting in a couple of swivel seats. By the time I sit and squirm around on that bench seat for a fishing trip, my back is hurting so bad I can hardly get out of the boat.

By the time I sit and squirm around on that bench seat for a fishing trip, my back is hurting so bad I can hardly get out of the boat.

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I hear you on that one. Those bench seats will kill your back. Thats why I want to redo the whole back end of mine. It's just very uncomfortable and awkward. I figure if I can just find a way to sit sideways in the boat and further back towards the motor It will be alot better. Then I can mount a seat.

Shortbus, I have a 16 48 landau that I removed all of the bench seats. Been running it that way for 2 years, no problems so far. Have had a couple of big boys in there with me on some big rough water. Will post some pics tomorrow.

Shortbus, I have a 16 48 landau that I removed all of the bench seats. Been running it that way for 2 years, no problems so far. Have had a couple of big boys in there with me on some big rough water. Will post some pics tomorrow.

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Awesome, thats the same boat I have. what size motor do you run? I have a 25 horse merc on mine and it scoots it allong fairly well. I had a 9.9 on it but it was way to slugish. My boat only has the rear bench in it.

short, this is what i did to my 1648 monark ... 2 yrs ago i started by putting in aluminum angle over each floor rib,,, did away with the factory gussets and put in aluminum angle gussets,,,, then last yr i took out the front bench seat, 20" wide... it was not attached to the floor so i just needed integrity on the sides of the boat......... here i put 2 runs of 1" x 2" aluminum tubing, down each side ... from the front "side" rib to the last rib at the back seat......my boat is way more sound now than it was from the factory... I STILL NEED TO FIGURE OUT SOME FLOATATION..........i run a 50 hp engine in the misipy river, so the boat takes a beating on every trip , but i wish i had done these modifications 10 yrs ago.....................

Shortbus, here are the pics of my jonboat. The boxes are boat gas tanks that failed QC. cut the tops out and used 1/2 inch plywood for the new top. Rear seat has a 8 inch offset, gets you off to the side make running the boat more comfortable and easier. Front seat is the same except no offset. I had trolling motor batteries under the front seat and used the back for life jackets, seat cushion etc.

i have a 16 48 grumann 1998 model it seems to be a very sturdy built jon

i too have a desire to remove the rear bench and i love that open area look in bams jon .

i think i would take the bench out and reuse it in a modified way by makeing 2 boxes and have that middle open so i can sit sideways and steer my 35 horse
i have one of those offset pedestal brackets that i use now and although it works better than just haveing the seat mounted in the middle of the bench
its still lacking in comfort.